Sunburn creams don't stop cancer

They fear that holidaymakers may have been lulled into a false sense of security and increased their risk by staying out in the sun too long.

Researchers have discovered that the sun's ultraviolet rays can cause potentially fatal damage deep under the skin's surface.

The dangerous changes were caused mainly by UVA rays, one of the three types of invisible beams.

These have been associated with premature skin ageing but not - until now - cancer. Suntan lotions, however, give maximum protection against another type, UVB rays.

These cause surface burns and had always been considered the main cause of cancer. According to the latest study, this means that lotions and creams fail to fully block harmful rays that can cause cancer although they can help prevent sunburn.

The findings also add to concerns about sunbeds, which are used by three million Britons - mainly women - as they give out mainly UVA rays.

Professor Gary Halliday, lead author of the study at the University of Sydney, said the discovery had 'profound implications on public health worldwide'.

Malignant melanoma, the most serious form of skin cancer, kills more than 1,600 people a year in the UK and around 7,000 cases are diagnosed annually.

Young people are twice as likely to suffer from skin cancer now as 20 years ago. Sales of sun creams are worth £146million a year, an all-time high figure. They have a 'factor' rating for the level of protection against UVB light.

A little-known star system - normally printed on the back of bottles - relates to the protection against UVA.

Dr Claire Linge, head of cell biology at the RAFT Institute for Plastic Surgery in Middlesex, said: 'Our advice is to be sensible. Use creams to protect you in the sun but don't use them to prolong your stay in the sun.

'We have known for some time that UVA light has been getting through to the deepest layers of skin.

'But some scientists have argued that, as it does not hold as much energy as UVB, it cannot be causing cancer.

'Now, this study shows that it has caused damage to the genetic material of DNA. This adds to the suspicion that UVA is the biggest cause of malignant melanoma.'

In the study, biopsies were taken from 16 patients with two forms of non-melanoma skin cancer, reports the U.S. journal Proceedings of the National Academy of Sciences.

In both types, they found that the basal layer - deep under the surface of the skin - contained significantly more damaged cells bearing UVA 'fingerprints' than signs of UVB damage.

Experts said changes in the DNA in the basal layer are 'potentially critical' as they give tumours a greater chance to spread than if damage is limited to the outer layer.

'UVA may make a larger contribution to skin cancer than is generally assumed,' said Professor Halliday.

'The importance of protecting the population not just from UVB but also from UVA irradiation has profound implications on public health worldwide.'

The study shows that UVA rays can cause non-melanoma skin cancers. This is rarely life-threatening and is the most common form of cancer in the UK with more than 62,000 cases a year.

Researchers said the findings were likely to be as relevant to malignant melanoma as this also stems from damage to the basal skin layer.

Malignant melanoma has killed 8,100 Britons in five years compared to 4,900 in Australia, where wearing T-shirts and hats in the sun is common practice.

One in 68 British adults will be diagnosed with melanoma at some point in their life. This is forecast to rise to one in 50 by 2010.

Dr Catherine Harwood, a dermatologist at Cancer Research UK, said: 'This is an important paper which adds data to the growing body of evidence pointing to a significant role for UVA in the development of skin cancer.'

A spokesman for Boots said the store has launched a sun cream offering the highest ever level of UVA protection.

The findings will also concern sunbed users as tanning lamps use mainly UVA rays. Studies suggest the chances of getting skin cancer rise by up to 20 per cent for each decade of sunbed use.

Kathy Banks, chief executive of the Sunbed Association, said: 'If people tan sensibly and moderately indoors and outdoors without over-exposing themselves then they can minimise the risks.'

Vitamin D 'lifesaver' Women can reduce the risk of breast cancer by eating a diet rich in vitamin D, say experts. It is hailed as a potential weapon against a disease claiming 13,000 lives a year in Britain.

Researchers found that breast tissue has the power to activate the cancer-fighting properties of vitamin D provided the body has enough stored up to draw on.

Good sources include oily fish, eggs, milk - and the rays of the sun. But slimmers who cut out vitamin D-rich milk and dairy produce could unwittingly increase the risk of the disease.

Experts at the British Endocrine Societies' annual meeting in Brighton yesterday called for an overhaul of women's diets to boost vitamin D.

The findings follow research by Dr Martin Hewison, an endocrinologist from Birmingham University, and colleagues from St George's Hospital Medical School, in London.